package the.offer.DataStructure.Impl;

public class Array<E> {

    private E[] data;
    private int size;

    public Array() {
        this(10);
        size = 0;
    }

    public Array(int capacity) {
        data = (E[]) new Object[capacity];
        size = 0;
    }

    public Array(E[] data) {
        this.data = data;
        size = data.length;
    }

    public int getSize() {
        return size;
    }

    public int getCapacity() {
        return data.length;
    }

    public boolean isEmpty() {
        return size == 0;
    }


    public void add(int index, E e) {
        if (index < 0 || index > size)
            throw new IllegalArgumentException("Add failed. Index is illegal.");

        if (size == data.length)
            resize(2 * data.length);

        for (int i = size - 1; i >= index; i--)
            data[i + 1] = data[i];
        data[index] = e;
        size++;
    }

    public void addFirst(E e) {
        add(0, e);
    }

    public void addLast(E e) {
        add(size, e);
    }

    public E get(int index) {
        if (index < 0 || index > size)
            throw new IllegalArgumentException("Get failed. Index is illegal.");
        return data[index];
    }

    public E getFirst() {
        return get(0);
    }

    public E getLast() {
        return get(size - 1);
    }


    void set(int index, E e) {
        if (index < 0 || index > size)
            throw new IllegalArgumentException("Set failed. Index is illegal.");
        data[index] = e;
    }

    public boolean contains(E e) {
        for (int i = 0; i < size; i++) {
            if (data[i] == e)
                return true;
        }
        return false;
    }

    public int findFirst(E e) {
        for (int i = 0; i < size; i++) {
            if (data[i] == e) {
                return i;
            }
        }
        return -1;
    }

    public int findLast(E e) {
        for (int i = size - 1; i >= 0; i--) {
            if (data[i] == e) {
                return i;
            }
        }
        return -1;
    }

    public E remove(int index) {
        if (index < 0 || index > size)
            throw new IllegalArgumentException("Remove failed. Index is illegal.");
        E ret = data[index];
        for (int i = index + 1; i < size; i++)
            data[i - 1] = data[i];
        size--;
        data[size] = null;
        if (size == data.length / 4 && data.length / 2 != 0)
            resize(data.length / 2);
        return ret;
    }

    public E removeFirst() {
        return remove(0);
    }

    public E removeLast() {
        return remove(size - 1);
    }

    public boolean removeElement(E e) {
        int index = findFirst(e);
        if (index != -1) {
            remove(index);
            return true;
        }
        return false;
    }

    public int removeAllElement(E e) {
        int ret = 0;
        for (int i = 0; i < size; i++) {
            if (data[i] == e) {
                ret++;
            } else {
                data[i - ret] = data[i];
            }
        }
        size = size - ret;
        if (size == data.length / 4 && data.length / 2 != 0)
            resize(data.length / 2);
        return ret;
    }

    private void resize(int newCapacity) {
        E[] newData = (E[]) new Object[newCapacity];
        for (int i = 0; i < size; i++)
            newData[i] = data[i];
        data = newData;
    }

    @Override
    public String toString() {
        StringBuilder res = new StringBuilder();
        res.append(String.format("Array: size=%d, capacity=%d\n", size, data.length));
        res.append('[');
        for (int i = 0; i < size; i++) {
            res.append(data[i]);
            if (i != size - 1)
                res.append(", ");
        }
        res.append(']');
        return res.toString();
    }
}
